Showing 4 results for Power Sharing
M. Ghani Varzaneh, A. Rajaei, M. Fakhraei,
Volume 13, Issue 3 (9-2017)
Abstract
This paper presents a new structure to provide the ability for power sharing of two Z-source inverters. According to the operation principles of Z-source inverters, only one input source supplies the circuit, which is a limitation particularly for the stand alone systems feeded by limited output power such as photovoltaics and feul cells. Furthermore; if one source fails to supply, the load can't be supplied. This paper covers those via interconnection of impedance network of two Z-source inverters. The operating principles of the proposed topology for the stand-alone and power sharing conditions are described and the relations are derived. The topology is simulated, which the results verify the theoretical analysis and well performance of the system.
M. Norianfar, S. Karimi, H. M. Cheshmehbeigi,
Volume 16, Issue 3 (9-2020)
Abstract
This paper suggests a new control method to modify the virtual impedance performance in unbalanced conditions. The proposed method compensates the voltage drop that occurred due to the virtual impedance and adjusts the voltage of the point of common coupling at a desirable level. To compensate the voltage drop, the reference voltage in the droop control varies according to the proposed algorithm. Moreover, a modified decoupled double synchronous reference frame is introduced to achieve appropriate active and reactive power sharing and voltage balancing, simultaneously. Finally, the simulation results in MATLAB/Simulink are provided to validate the accuracy and effectiveness of the proposed approach.
S. M. Alavi, R. Ghazi,
Volume 18, Issue 1 (3-2022)
Abstract
One of the significant concerns in the MTDC systems is that voltage source converters (VSCs) do not hit their limits in the post-contingency conditions. Converters outage, DC line disconnection, and changeable output power of wind farms are the most common threats in these systems. Therefore, their destructive impact on neighboring AC systems should be minimized as much as possible. The fixed droop control is a better choice than others to deal with this, although it also has some limitations. Accordingly, a novel centralized droop-based control strategy considering N-1 contingency is proposed in this paper. It prevents converters from exceeding their limits while causes optimal power sharing and minimum DC link voltage deviation immediately, without secondary control layer. It also utilizes maximum wind power without curtailment. These properties improve the performance of the MTDC system in post-contingency conditions. The effectiveness of the proposed control method is validated by simulation of a 4-terminal VSC-MTDC system in MATLAB/Simulink R2016a.
Mitesh Kumar, Shivam Shivam,
Volume 18, Issue 4 (12-2022)
Abstract
The idea of a microgrid is created by utilizing more diverse ac or dc distributed generation (DG) sources along with an energy storage system (ESS) and loads. The most efficient and reliable selection of ac and dc microgrids is a hybrid ac/dc microgrid. The hybrid microgrid largely overcomes the shortcomings of standalone ac or dc microgrids. A bidirectional interlinking converter (BIC) is utilized in the interface for controlling power flow between subgrids. In order to improve voltage and frequency regulation with effective power sharing, the BIC based on the proposed control scheme is implemented for power flow between ac and dc sub-grid in Islanding mode. The control scheme is modified based on conventional droop control with voltage and frequency variation in order to improve bus voltage and frequency regulation with effective power sharing for intermittent sources. The operation of the islanded hybrid ac/dc microgrid is performed with solar, wind, and energy storage system under variable generation and load conditions. In order to make robustness of the system, there are considered different cases for generation and load scenarios. In the transient state, the overshoot and settling time of frequency and voltage are improved, as well as the frequency and voltage regulations are found within the permissible limit in the steady state. Furthermore, the corresponding variations are shown in tabular form in the simulation result. The actual data of solar irradiance and wind speed have been taken from the National Renewable Energy Laboratory. The performance of the system is verified in MATLAB/Simulink environment.
